In Season 1 Episode 10 "Seeing Red" Dexter goes to Rita's ex-husbands motel room to search for evidence to allow him to take care of Paul "23:17", after this scene you see Dexter driving along in his boat where he pulls up to a cement dock where he walks to the bow of the boat and picks up the rope and jumps off to tie it up to the white post, at this scene if you look to the right you can clearly see the stern line already tied to the post "24:55", How did this get tied?